Coaxial via hole and process of fabricating the same

ABSTRACT

A coaxial via hole structure used in a carrier is disclosed. The coaxial via hole includes an outer cylinder-shaped conductor, an inner cylinder-shaped conductor and an intermediate fill. The outer cylinder-shaped conductor extends along a first direction. The inner cylinder-shaped conductor is disposed in the outer cylinder-shaped conductor and also extends along the first direction. The intermediate fill is between the outer cylinder-shaped conductor and the inner cylinder-shaped conductor and is made of insulating material or electrical-resistant material. The coaxial via hole structure can be applied as a capacitor or a resistor and has the function of signal shielding.

[0001] This application incorporates by reference Taiwanese applicationSerial No. 089116185, Filed Aug. 11, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates in general to a structure of a coaxial viahole, and more particularly to a coaxial via hole, which can be appliedas a capacitor or a resistor and has the function of signal shielding.

[0004] 2. Description of the Related Art

[0005] The development and progress of the IC (Integrated Circuit)integration and fabrication and the advance of device package andcircuit design is always aimed to be smaller and lighter.

[0006] Conventionally, capacitor is fixed on the circuit board bySurface Mounted Technique (SMT), as shown in FIG. 1. The capacitor 102is fixed on the pad 104 and the pad 104 is fixed on the circuit board(not shown). Trace 106 connects the pad 104 and via 108 on the circuitboard. However, capacitor 102 fixed by SMT occupies large surface area,which is against the aim of size shrinking.

[0007] Via capacitors within substrate is proposed, with the developmentof high dielectric constant material. A typical one is disclosed in aU.S. Pat. No. 5,055,966. FIG. 2A shows the structure of the viacapacitor within the multi-layer substrate; FIG. 2B is thecross-sectional view of the structure in FIG. 2A; FIG. 2C is theequivalent circuit of the capacitor at multi-layer substrate. Thecircuit board contains substrates L1, L2, L3, L4 and L5. A via 203 isformed in the substrate L3 and the via 203 is filled with dielectric.The conductive trace 204 above the via 203, the conductive trace 206below the via 203 and the via 203 itself together form a capacitor. Thecapacitance C thereof is a function of the thickness of the substrateL3, the diameter of the via 203 and the dielectric constant of thedielectric.

[0008] Referring to FIGS. 3A to 3C, another structure of theconventional inter-layer capacitor is disclosed in U.S. Pat. No.5,972,231, which contains two conductive plates 302, 304 of polygonalshape on top and bottom of the substrate 306. The conductive plates 302,304 are coupled to surrounding circuitry at the polygonal verticesthrough conductive traces 308, 310, respectively. The inter-layercapacitor can be further extended to be a capacitor between multi-layersubstrates by using via holes.

[0009] The two conventional capacitors mentioned-above occupy smallerhorizontal surface but more substrate layers. However, increasing numberof substrate layer is not acceptable for some Printed Circuit Boards(PCBs) with high device density. Similar problems also occur in theresistor structure.

SUMMARY OF THE INVENTION

[0010] It is therefore an object of the invention to provide a coaxialvia hole used in a carrier, includes an outer cylinder-shaped conductor,an inner cylinder-shaped conductor, and an insulating fill. The outercylinder-shaped conductor extends along the first direction. The innercylinder-shaped conductor is in the outer cylinder-shaped conductor andextends along the first direction. The insulating fill is between theouter cylinder-shaped conductor and the inner cylinder-shaped conductor.It is therefore another object of the invention to provide a method ofmanufacturing a coaxial via hole. First, the first hole is formed in acarrier. A process to make the first hole become conduct electricity isthen performed to form an outer cylinder-shaped conductor on theinterior of the first hole. Next, an insulating material is placed inthe outer cylinder-shaped conductor to form an insulating fill. Thesecond hole in the insulating fill is then formed. The second hole has adiameter smaller than the diameter of the first hole. Next, a process tomake the second hole become conduct electricity is performed to form aninner cylinder-shaped conductor on the interior of the second hole.

[0011] It is therefore another object of the invention to provide acoaxial via hole used in a carrier. The coaxial via hole includes anouter cylinder-shaped conductor, an inner cylinder-shaped conductor andan electrical-resistant fill. The outer cylinder-shaped conductorextends along the first direction. The inner cylinder-shaped conductoris in the outer cylinder-shaped conductor and extends along the firstdirection. The electrical-resistant fill is between the outercylinder-shaped conductor and the inner cylinder-shaped conductor.

[0012] It is therefore a further object of the invention to provide amethod of manufacturing a coaxial via hole. First, the first hole isformed in a PCB. A process to set hole become conduct electricity isthen performed to form an outer cylinder-shaped conductor on theinterior of the first hole. Next, an electrical-resistant material isplaced in the outer cylinder-shaped conductor to form anelectrical-resistant fill. The second hole in the electrical-resistantfill is then formed. The second hole has a diameter smaller than thediameter of the first hole. Next, a process to set hole become conductelectricity is performed to form an inner cylinder-shaped conductor onthe interior of the second hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other objects, features, and advantages of the invention willbecome apparent from the following detailed description of the preferredbut non-limiting embodiments. The description is made with reference tothe accompanying drawings in which:

[0014]FIG. 1 (Prior Art) illustrates a conventional SMT capacitor;

[0015]FIG. 2A (Prior Art) shows the structure of the via capacitorwithin the multi-layer substrate;

[0016]FIG. 2B (Prior Art) is the cross-sectional view of the structurein FIG. 2A;

[0017]FIG. 2C (Prior Art) is the equivalent circuit of the capacitor atmulti-layer substrate;

[0018]FIGS. 3A to 3C (Prior Art) show another structure of theconventional inter-layer capacitor disclosed in U.S. Pat. No. 5,972,231;

[0019]FIGS. 4A to 4B show a pillar-shaped capacitor according to apreferred embodiment of the invention;

[0020]FIG. 4A is the three-dimensional drawing of the pillar-shapedcapacitor and FIG. 4B is the top view of the pillar-shaped capacitor;

[0021]FIG. 5 (Prior Art) is a three-dimensional view of a PCB with viaholes;

[0022]FIG. 6A shows a coaxial via holes according to a preferredembodiment of the invention;

[0023]FIG. 6B shows another coaxial via holes according to a preferredembodiment of the invention;

[0024]FIG. 7A is the cross-sectional view showing the coaxial via holein FIG. 6 while it is used as a capacitor;

[0025]FIG. 7B is the equivalent capacitor symbol of the capacitor shownin FIG. 7A;

[0026]FIG. 8 shows how the coaxial via hole according to a preferredembodiment of the invention is applied to a coaxial PCB;

[0027]FIG. 9A (Prior Art) shows a conventional capacitor used by acomponent on a PCB;

[0028]FIG. 9B (Prior Art) shows a capacitor of the invention used by acomponent on a PCB;

[0029]FIG. 10A (Prior Art) shows a conventional conductive trace havingthe function of noise shielding;

[0030]FIG. 10B shows a conductive trace having the function of noiseshielding according to a preferred embodiment of the invention;

[0031]FIG. 10C is the horizontal cross section of the conductive traceshown in FIG. 10B;

[0032]FIG. 11 is the lateral view of a computer system structure, whichuses the coaxial via hole of the invention as a capacitor;

[0033]FIG. 12 (Prior Art) is the top view of a conventional moduleboard;

[0034]FIG. 13 is the top view of a module board with the coaxial viahole type capacitor according to a preferred embodiment of theinvention;

[0035]FIG. 14 (Prior Art) is the cross section of a conventionalconnector;

[0036]FIG. 15 (Prior Art) is the top view of the conventional pinarrangement of a high frequency circuit;

[0037]FIG. 16 is the cross section of a connector having the coaxial viahole structure according to a preferred embodiment of the invention; and

[0038]FIG. 17 shows a resistor having the coaxial via hole structureaccording to a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0039]FIGS. 4A to 4B show a pillar-shaped capacitor according to apreferred embodiment of the invention; FIG. 4A is the three-dimensionaldrawing of the pillar-shaped capacitor and FIG. 4B is the top view ofthe pillar-shaped capacitor. Dielectric is filled in between theconductor 402 and the conductor 404 to form an insulating fill 406. Theinsulating fill 406, conductor 402 and conductor 404 together form apillar-shaped capacitor 400. The conductor 402 and conductor 404 can beboth coaxially cylinder-shaped and with different diameters. Thecapacitance is in proportion to the dielectric constant and conductorsurface and is in inverse proportion to the distance between twoconductors. The configuration of the pillar-shaped capacitor can bemodified when needed but is not limited to the shape shown in thedrawings.

[0040] A three-dimensional view of a PCB with via holes is shown in FIG.5. The PCB 500 contains a number substrate layers. Signal is transmittedbetween different substrate layers by a via hole 510. The via hole 510connects the conductive trace 504 of the first layer 502 and theconductive trace 508 of another substrate layer 506. According to apreferred embodiment of the invention, the function of the via hole 510can be further extended so that a combined structure of a via hole and apillar-shaped capacitor is proposed.

[0041]FIGS. 6A and 6B show two coaxial via holes according to apreferred embodiment of the invention, which can be formed by thefollowing procedure. First, a hole 604 is formed through a substrate602. To make the interior of the hole 604 become conduct electricity isthen performed to form a relatively large diameter cylinder-shapedconductor 606. Then, dielectric with high dielectric constant is placedin the cylinder-shaped conductor 606 to form an insulating fill 608.Another hole 610 with smaller diameter than the hole 604 is then formedin the insulating fill 608. The interior of the hole 610 is then madeconduct electricity to form a cylinder-shaped conductor with arelatively small diameter. The process to make the interior of the holes604, 610 become conduct electricity is preferrably by plating or placingconductive paste.

[0042] Holes 604, 610 are preferrably formed by photo formation or drillformation, such as mechanically drilling, laser-drilling ablation orplasma ablation. The process to make the interior of the holes 604, 606become conduct electricity can be completed by plating or placingconductive paste. Moreover, high dielectric constant insulating materialcan be placed in the outer cylinder-shaped conductor 606 by plugging orlaminating insulating material.

[0043] According to the process mentioned above, the coaxial via holewith the outer cylinder-shaped conductor 606, the inner cylinder-shapedconductor 612 and the insulating fill 608 therebetween is then formed.The outer cylinder-shaped conductor 606 extends along the Z-axis, whichis vertical to substrate 602. The inner cylinder-shaped conductor 612also extends along the Z-axis can is disposed in the outercylinder-shaped conductor 606. The insulating fill 608 is between thetwo cylinder-shaped conductors 606, 612 and separates the two. Whilemulti layers of substrate are used, the coaxial via hole of theinvention can be also applied to connect more than one layer ofsubstrate.

[0044] As shown in the drawings of FIG. 4A and FIG. 4B, cylinder-shapedconductors are taken as examples of the inner and outer conductors 404,402. However, the coaxial via hole of the invention is not limitedthereto. On the contrary, the inner and outer conductors can be in anyshape only if the two conductors extend along with the Z-axis and arecompletely separated by an insulating fill. Therefore, anyconfigurations of the two conductors with cross sections shaped in, forexample, circle, oval, rectangle are within the scope of the invention.Moreover, the configuration and the cross-section of the inner and outerconductors can be different from each other.

[0045] The conductor 614 connected to the outer cylinder-shapedconductor 606 as shown in FIG. 6A and FIG. 6B is formed along with thefabrication process mentioned above. Also, a similar conductor 620connected to the inner cylinder-shaped conductor 612 as shown in FIG. 6Bis formed. Electrical trace can be therefore connected to the inner andouter conductor via the conductor 620, 612, 606 or 614.

[0046] The inner conductor 612 is cylinder-shaped while it is formed byplating. However, the inner conductor 612 is solid pillar-shaped whileit is formed by filling conductive paste (referring to FIG. 8). It isthere clear to people who are skilled in the art that the two shapes andfabricating processes are both within the scope of the invention.

[0047] Material of the insulating fill 608 greatly influences theperformance of the coaxial via hole of the invention, particularly whilethe coaxial via hole is used as a capacitor. Because the equivalentcapacitance of a capacitor is in proportion to the dielectric constantof the insulating material between the two conductive layers, insulatingmaterial with high dielectric constant is preferred. Insulatingmaterials such as ceramic powder and mixture of polymer with dielectricconstant up to 60 are produced by DuPont and HADCO and are preferred forusing in the coaxial via hole of the invention.

[0048]FIG. 7A is the cross-sectional view showing the coaxial via holein FIG. 6 while it is used as a capacitor and FIG. 7B is the equivalentcapacitor symbol thereof. The inner conductor 612 is connected to theconductor P1, which is connected to a positive voltage source (VCC) atthe other end. The outer conductor 606 is connected to the conductor P2,which is connected to a negative voltage source (GND). To function as acapacitor, the inner conductor 612 and the outer conductor 606 arecharged differently.

[0049] The capacitance of the capacitor of the invention is alsodetermined by the configuration and size of the inner conductor 612 andthe outer conductor 606, besides the dielectric constant of theinsulating fill 608. To where the conductor P1, P2 are connected to theinner and outer conductor layers are also criteria of the capacitance,while the cross sections of the conductors are not symmetrical.Moreover, more than two capacitors with the coaxial via hole structureof the invention can be connected in parallel to adjust the capacitancewhen needed.

[0050]FIG. 8 shows how the coaxial via hole according to a preferredembodiment of the invention is applied to a multi-layer PCB. The PCB 800includes 8 conductive layers L1˜L8. In FIG. 8, the coaxial via hole ofthe invention penetrates through the conductive layer L3 to L6. Theinner conductor 612 is connected to the conductive trace 808; the outerconductor 606 is connected to the conductive trace 810. The insulatingfill 812 would be the same material with insulating fill 608 orconventional dielectric material. The inner conductor 612 and the outerconductor 606 are separated by the insulating fill 608. The conductivetrace 808 is connected to a source of positive voltage and theconductive trace 810 is connected to a source of negative voltage. Thecoaxial via hole disposed between conductive layer L3 and L6 is only anexample. On the contrary, the coaxial via hole of the invention can beconfigured to penetrate either a portion of the PCB 800, such as throughlayer L3 to L6, or to penetrate the PCB 800, i.e. through all the 8conductive layers. Moreover, the conductive trace 808 may be connectedto negative voltage source and the conductive trace 810 may be connectedto positive voltage source when needed.

[0051]FIG. 9A shows a conventional capacitor used by a component on aPCB and FIG. 9B shows a capacitor of the invention used by a componenton a PCB. The component 902 on the PCB (not shown) includes a number ofpins (not shown). Pad 904 of the pin is connected to a positive powersource. To keep the voltage steady and eliminate the influence of thenoise produced by power source, the pin of the component 902, which isconnected to power source, is usually connected to a bypass capacitorvia the pad 904. Referring to FIG. 9A, the pin 904 is connected to thefirst inner plane (not shown) through the conductive trace 906 and thevia hole 908; the capacitor 910 is connected to the first inner plane(not shown) through the conductive trace 912 and the via hole 914. Theother end of the capacitor 910 is connected to the second innerplane(not shown) through the conductive trace 916 and the via hole 918.

[0052] In FIG. 9B, the pin 904 is connected to the capacitor 922, thestructure of which is made according to the coaxial via hole of theinvention, through the conductive trace 920. The coaxial via hole typecapacitor 922 is directly connected to the second inner plane.

[0053] Conventionally, referring to FIG. 9A, the path of energy flowfrom the capacitor 910 to the component 902 includes the capacitor 910,the conductive trace 912, the via hole 914, the via hole 908, theconductive trace 906, and the pin 904. According to a preferredembodiment of the invention, energy stored in the capacitor 922 can betransmitted to the component 902 simply by passing through theconductive trace 920 and the pad 904 of the pin. Therefore, the speed ofenergy transmission between the capacitor 922 of the invention and thecomponent 902 is highly increased. Consequently, the component 902 usingthe capacitor 922 of the invention is able to switch voltage level morerapidly than the conventional one. So the component 902 performsnormally even at high frequency. It is therefore obvious that circuitusing a capacitor with the coaxial via hole structure is more suitable,than the conventional one, to the rapid voltage level switch highfrequency system.

[0054] The coaxial via hole structure according to a preferredembodiment of the invention further has the function of noise shielding.FIG. 10A shows a conventional conductive trace having the function ofnoise shielding; FIG. 10B shows a conductive trace having the functionof noise shielding according to a preferred embodiment of the invention;and FIG. 10C is the horizontal cross section of the conductive traceshown in FIG. 10B.

[0055] In a conventional circuit system, grounded trace 1003 is usuallyused to coil around a sensitive conductive trace 1001 so that noise canbe shielded and the resistance of the conductive trace 1001 can be undercontrol. The grounded trace 1003 prevents the conductive trace 1001 frombe interrupted by the environmental noise and also avoids the noise ofthe conductive trace 1001 to interrupt the environment. The conventionalgrounded trace 1003 only provides the function of noise shielding toconductive traces on the same layer of substrate. However, while theconductive trace may extend through a via hole to another layer of thesubstrate, there is no protection of the conductive trace at the viahole.

[0056] According to a preferred embodiment of the invention, the innercylinder-shaped conductor layer 1002 is connected to the conductor P1;the outer cylinder-shaped conductor layer 1004 is connected to theconductor P2, as shown in FIG. 10B. The conductor P2 is grounded and theconductor P1 is connected to a general signal trace. As shown in FIG.10C, the whole structure of the coaxial via hole is configured like aco-axial electric cable. Consequently, the outer cylinder-shapedconductor layer 1004 provides the protection of noise shielding for theinner cylinder-shaped conductor 1002. Also, the resistance can beproperly designed to be consistent.

[0057] It is apparent for people who are skilled in the art that theinsulating fill between the two conductor layers is not limited to highdielectric constant material while the coaxial via hole of the inventionis used to provide the function of noise shielding.

[0058] In the above description, the coaxial via hole of the inventionis used in a PCB. How, PCB is only an example of various carriers. It isapparent that the coaxial via hole according to a preferred embodimentof the invention can also be applied in an IC socket, adapter, aconnector, heat sink or the like. Two of the carriers are taken asexamples for illustration.

[0059]FIG. 11 is the lateral view of a computer system structure, whichuses the coaxial via hole of the invention as a capacitor. The computersystem in FIG. 11 includes Central Process Unit (CPU) 1102, north bridgeIC 1104 and south bridge 1106. CPU 1102 is disposed on the IC socket1108. The IC socket 1108 is connected to the adapter 1112 through anumber of solder balls 1110. The adapter 1112, north bridge IC 1104, andsouth bridge IC 1106 are connected to the module board 1114 throughsolder balls 1110. The standoff board 1116 is connected to the moduleboard 1114 and the carrier board 1118.

[0060]FIG. 12 is the top view of a conventional module board 1114 asshown in FIG. 11. The module board 1114 includes a component weldingregion 1202 for connecting with the adapter 1112. The soldering region1202 contains a number of pads 1204 corresponding to the pins connectedto VCC at CPU 1102. Ideally, at CPU 1102, each pin connected to VCCneeds a capacitor. Conventionally, the pin is connected to a capacitor1208 through a pad 1204 and a via hole 1206. The capacitor is typicallya Surface Mounted Device (SMD) capacitor 1208. However, as shown in FIG.12, these SMD capacitors 1208 occupies large usable area of the moduleboard 1114, which consequently limits the application of the moduleboard 1114.

[0061]FIG. 13 is the top view of a module board with the coaxial viahole type capacitor according to a preferred embodiment of theinvention. The module board 1300 includes a soldering region 1302 forconnecting with the adapter 1112. The soldering region contains a numberof pads 1304 corresponding to pins connected to VCC at CPU 1102. The viahole 1306, which the pad 1304 is connected to, can be configured to havethe structure and function of the coaxial via hole type capacitoraccording to a preferred embodiment of the invention. Thus, less area ofthe module board is used for the capacitor and more area of the moduleboard can be used for other component.

[0062] The coaxial via hole of the invention can be used not only in thevia hole on the module board but also the adapter 1112 and the IC socket1108 so that the adapter 1112 and the IC socket 1108 can have theadvantages of more area for other components.

[0063]FIG. 14 is the cross section of a conventional connector. Theconnector in FIG. 14 includes a male connector 1402 and a femaleconnector 1404. The pin 1406 of the male connector 1402 is inserted intothe contact 1408 of the female connector 1404. The contact 1408 fixesthe connector 1404 at the PCB 1410. The screw 1412 can fix the connector1404 and the PCB 1410 together.

[0064]FIG. 15 is the top view of the preferred pin assignment for a highfrequency circuit. Symbol S represents signal pin of the connector 1402,which outputs signals; symbol G represents grounded pin of the connector1402. Signal pins S are designed to be surrounded by grounded pins G sothat noise can be isolated from the signal pins and higher signalquality can be obtained. However, the grounded pins. G occupy large areaof the connector, which is against the goal of size minimization.

[0065]FIG. 16 is the cross section of a connector having the coaxial viahole structure according to a preferred embodiment of the invention. Theconnector 1604 includes a contact 1608 of a capacitor 1606 having acoaxial via hole structure according to a preferred embodiment of theinvention and contacts 1618, 1620, 1622, and 1624 of the coaxial viaholes 1610, 1612, 1614, and 1616 which functions as signal shielding.The screw 1628 connects the negative power source 1630 and the negativepower source 1632 together. The contact 1626 is connected to thegrounded pin of the connector 1602, so the contact 1626 does not need toconfigure as the coaxial via hole of the invention in order to have thefunction of signal shielding. The contact 1608 is connected to the powerpin of the connector 1602 and the positive power source 1634. To keepthe voltage steady, the connect 1608 is also connected to the capacitor1606. The outer cylinder-shaped conductor 1636 of the capacitor 1606 isconnected to the negative power source 1632 and the innercylinder-shaped conductor 1638 of the capacitor 1606 is connected to thepositive power source 1634 along the contact 1608. An insulating fill1640 with high dielectric constant is between the inner cylinder-shapedconductor 1638 and the outer cylinder-shaped conductor 1636. The outercylinder-shaped conductors, such as the conductor 1642, of the coaxialvia holes 1610, 1612, 1614, and 1616 are connected to a negative powersource 1632 in order to have the function of signal shielding. Thus, thecontacts 1618, 1620, 1622, and 1624 are prevented from the noiseinterference. Consequently, the pin number of the connector 1602 and theconnect number of the connector 1604 are both reduced and the area whichthe connector 1602 and the connector 1604 occupy are greatly reduced.

[0066] The coaxial via hole of the invention can also be applied in anIC socket, to which an IC with a number of pins are fixed. The structureis as shown in FIG. 16.

[0067] Further more, the insulating fill of the coaxial via holestructure of the invention can be replaced by an electrical-resistantmaterial to form a resistor. Desired resistance can be obtained bychoosing electrical-resistant material with different resistivity,modifying the diameters or the depth of the via hole. That is becausethe resistance is in proportion to the resistivity and length of thematerial and is in inverse proportion to the cross sectional area of thematerial. Please refer to FIG. 17, which shows a resistor having thecoaxial via hole structure according to a preferred embodiment of theinvention. The resistor with the coaxial via hole structure of theinvention penetrates through the substrate 1704. The innercylinder-shaped conductor 1712 is connected to the conductive trace1708. The conductive trace 1708 is further connected to the signaltrace, the positive voltage source or the negative voltage source. Theouter cylinder-shaped conductor 1714 is connected to the conductivetrace 1710. The conductive trace 1710 is further connected to the signaltrace, the positive voltage source or the negative voltage source. Theelectrical-resistant material 1716 is between the inner cylinder-shapedconductor 1712 and the outer cylinder-shaped conductor 1714. Theinsulating fill 1718 and the insulating fill 1720 separates the innercylinder-shaped conductor 1724 and the outer cylinder-shaped conductor1714. The resistor has the same function with discrete resistorcomponent. Each cylinder-shaped conductor 1714, 1712 would beindividually connected to a positive voltage source, a negative voltagesource or a signal net. The resistor in circuit would be a pull downresistor, while the outer cylinder-shaped conductor 1714 is connected tothe signal net through the conductive trace 1710 and the innercylinder-shaped conductor 1712 is connected to the negative voltagesource conductor 1708. The resistor in circuit would be a pull upresistor, while the inner cylinder-shaped conductor 1712 is connected tothe positive voltage source through the conductor 1708. The resistorwould be a terminator, while the inner cylinder-shaped conductor 1712 isconnected to the signal net through the conductor 1708. More over, theresistor with the coaxial via hole structure according to a preferredembodiment of the invention can also be applied in PCB, substrate, ICsocket, adapter, connector, heat sink of other carrier so that theobjective of using less area can be achieved.

[0068] Herein, a carrier with a substrate 1704 is taken as an example toillustrate the manufacturing process of a coaxial via hole as aresistor. First, a hole 1722 is formed through the substrate 1704. Theinterior of the hole 1722 is then set to become conduct electricity toform an outer cylinder-shaped conductor 1714. The interior of the outercylinder-shaped conductor 1714 is then formed with a resistant materialto form a resistant fill 1716. Another hole 1724 with smaller diameterthan the hole 1722 is then formed to penetrate through the resistantlayer 1716. The interior of the hole 1724 is then set to become conductelectricity to form a inner cylinder-shaped conductor 1712.

[0069] The capacitor with the coaxial via hole structure according to apreferred embodiment of the invention has the following advantagessuperior to the conventional SMD capacitor.

[0070] (1) The capacitor with the coaxial via hole structure occupiesmuch less surface area than the conventional SMD capacitor.

[0071] (2) The capacitor with the coaxial via hole structure of theinvention can be used in inner layers of a PCB but the SMD capacitor canbe only used on the surface layers of PCB.

[0072] (3) The capacitor with the coaxial via hole structure of theinvention can be built in the substrate but the SMD capacitor can not beapplied inside the multi-layer substrate.

[0073] (4) The capacitor with the coaxial via hole structure of theinvention is more suitable for the high frequency circuit than theconventional SMD capacitor; and the capacitor of the invention can alsofunction as signal shielding.

[0074] The resistor with the coaxial via hole structure according to apreferred embodiment of the invention has the following advantages priorto the conventional SMD resistor.

[0075] (1) The resistor with the coaxial via hole structure occupiesmuch less surface area than the conventional SMD resistor.

[0076] (2) The resistor with the coaxial via hole structure of theinvention can be used in inner layers of a PCB but the SMD resistor canbe only used on the surface layers of PCB.

[0077] (3) The resistor with the coaxial via hole structure of theinvention can be buried in the substrate but the SMD resistor can not beapplied inside the multi-layer substrate.

[0078] (4) The resistor with the coaxial via hole structure of theinvention effectively shortens the trace path and reduces signal lossand delay, which is superior to the conventional SMD resistor in termsof electrical characteristics.

[0079] To sum up, the capacitor or resistor with the via hole structureof the invention has the advantages of occupying much less surface ofthe substrate or intra-layer surface, being able to be built in thesubstrate or other carrier without extra discrete capacitor, resistorand the cost thereof, and also functioning as signal shielding.

[0080] While the invention has been described by way of example and interms of the preferred embodiment, it is to be understood that theinvention is not limited to the disclosed embodiment. To the contrary,it is intended to cover various modifications and similar arrangementsand procedures, and the scope of the appended claims therefore should beaccorded the broadest interpretation so as to encompass all suchmodifications and similar arrangements and procedures.

What is claimed is:
 1. A coaxial via hole used in a carrier, comprising:an outer cylinder-shaped conductor extending along a first direction; aninner cylinder-shaped conductor in the outer cylinder-shaped conductor,wherein the inner cylinder-shaped conductor extends along the firstdirection; and an insulating fill between the outer cylinder-shapedconductor and the inner cylinder-shaped conductor.
 2. The coaxial viahole as claimed in claim 1, wherein the first direction is vertical to adirection along which the carrier extends.
 3. The coaxial via hole asclaimed in claim 1, wherein the carrier is a printed circuit board(PCB).
 4. The coaxial via hole as claimed in claim 1, wherein thecarrier is a substrate.
 5. The coaxial via hole as claimed in claim 1,wherein the carrier is an Integrated Circuit (IC) socket.
 6. The coaxialvia hole as claimed in claim 1, wherein the carrier is an adapter. 7.The coaxial via hole as claimed in claim 1, wherein the carrier is aconnector.
 8. The coaxial via hole as claimed in claim 1, wherein thecarrier is a heat sink.
 9. The coaxial via hole as claimed in claim 1,wherein the carrier at least comprises a conductive layer and thecoaxial via hole penetrates a portion of the carrier.
 10. The coaxialvia hole as claimed in claim 1, wherein the carrier at least comprises aconductive layer and the coaxial via hole penetrates the carrier. 11.The coaxial via hole as claimed in claim 1, wherein a cross section, ina direction vertical to the first direction, of the outercylinder-shaped conductor can shape as any configuration and wherein across section, in the direction vertical to the first direction, of theinner cylinder-shaped conductor can shape as any configuration.
 12. Thecoaxial via hole as claimed in claim 1, the inner cylinder-shapedconductor is connected to a negative voltage source.
 13. The coaxial viahole as claimed in claim 1, the inner cylinder-shaped conductor isconnected to a positive voltage source.
 14. The coaxial via hole asclaimed in claim 1, the inner cylinder-shaped conductor is connected toa signal conductor.
 15. The coaxial via hole as claimed in claim 1, theouter cylinder-shaped conductor is connected to a negative voltagesource.
 16. The coaxial via hole as claimed in claim 1, the outercylinder-shaped conductor is connected to a positive voltage source. 17.The coaxial via hole as claimed in claim 1, the outer cylinder-shapedconductor is connected to a signal conductor.
 18. The coaxial via holeas claimed in claim 1, further comprising: a conductor which isconnected to the inner cylinder-shaped conductor and is connected to anegative voltage source.
 19. The coaxial via hole as claimed in claim 1,further comprising: a conductor which is connected to the innercylinder-shaped conductor and is connected to a positive voltage source.20. The coaxial via hole as claimed in claim 1, further comprising: aconductor which is connected to the inner cylinder-shaped conductor andis connected to a signal conductor.
 21. The coaxial via hole as claimedin claim 1, further comprising a conductor which is connected to theouter cylinder-shaped conductor and is connected to a negative voltagesource .
 22. The coaxial via hole as claimed in claim 1, furthercomprising a conductor which is connected to the outer cylinder-shapedconductor and is connected to a positive voltage source.
 23. The coaxialvia hole as claimed in claim 1, further comprising a conductor which isconnected to the outer cylinder-shaped conductor and is connected to asignal conductor.
 24. The coaxial via hole as claimed in claim 1,wherein the insulating fill is made of a material with high dielectricconstant.
 25. A method of manufacturing a coaxial via hole, comprising:(a) forming a first hole in a carrier; (b) making the interior of thefirst hole conduct electricity to form an outer cylinder-shapedconductor; (c) placing an insulating material in the outercylinder-shaped conductor to form an insulating fill; (d) forming asecond hole in the insulating fill, wherein the second hole has adiameter smaller than the diameter of the first hole; and (e) making theinterior of the second hole conduct electricity to form an innercylinder-shaped conductor.
 26. The method of manufacturing a coaxial viahole as claimed in claim 25, wherein in said step (b), making theinterior of the first hole become conduct electricity to form an outercylinder-shaped conductor by plating.
 27. The method of manufacturing acoaxial via hole as claimed in claim 25 or 26, wherein in said step (e),making the interior of the second hole become conduct electricity toform an inner cylinder-shaped conductor by plating.
 28. The method ofmanufacturing a coaxial via hole as claimed in claim 25 or 26, whereinin said step (e), making the interior of the second hole become conductelectricity to form an inner cylinder-shaped conductor by placingconductive paste.
 29. The method of manufacturing a coaxial via hole asclaimed in claim 25, wherein in said step (c), the insulating materialis filled in the outer cylinder-shaped conductor by plugging.
 30. Themethod of manufacturing a coaxial via hole as claimed in claim 25,wherein in said step (c), the insulating material is filled in the outercylinder-shaped conductor by laminating.
 31. A coaxial via hole used ina carrier, comprising: an outer cylinder-shaped conductor extendingalong a first direction; an inner cylinder-shaped conductor in the outercylinder-shaped conductor, wherein the inner cylinder-shaped conductorextends along the first direction; and an electrical-resistant fillbetween the outer cylinder-shaped conductor and the innercylinder-shaped conductor.
 32. The coaxial via hole as claimed in claim31, further comprising: a conductor which is connected to the outercylinder-shaped conductor and is connected to a signal conductor. 33.The coaxial via hole as claimed in claim 31, further comprising: aconductor which is connected to the outer cylinder-shaped conductor andis connected to positive voltage source.
 34. The coaxial via hole asclaimed in claim 31, further comprising: a conductor which is connectedto the outer cylinder-shaped conductor and is connected to a negativesource.
 35. The coaxial via hole as claimed in claim 31, furthercomprising: a conductor which is connected to the inner cylinder-shapedconductor and is connected to a signal conductor.
 36. The coaxial viahole as claimed in claim 31, further comprising: a conductor which isconnected to the inner cylinder-shaped conductor and is connected to apositive voltage source.
 37. The coaxial via hole as claimed in claim31, further comprising: a conductor which is connected to the innercylinder-shaped conductor and is connected to a negative voltage source.38. The coaxial via hole as claimed in claim 31, wherein the carrier isa PCB.
 39. The coaxial via hole as claimed in claim 31, wherein thecarrier is a substrate.
 40. The coaxial via hole as claimed in claim 31,wherein the carrier is an IC socket.
 41. The coaxial via hole as claimedin claim 31, wherein the carrier is an adapter.
 42. The coaxial via holeas claimed in claim 31, wherein the carrier is a connector.
 43. Thecoaxial via hole as claimed in claim 31, wherein the carrier is a heatsink.
 44. The coaxial via hole as claimed in claim 31, wherein the firstdirection is vertical to a direction along which the carrier extends.45. The coaxial via hole as claimed in claim 31, wherein the carrier atleast comprises a conductive layer and the coaxial via hole penetrates aportion of the carrier.
 46. The coaxial via hole as claimed in claim 31,wherein the carrier at least comprises a conductive layer and thecoaxial via hole penetrates the carrier.
 47. A method of manufacturing acoaxial via hole, comprising: (a) forming a first hole in a carrier; (b)making the interior of the first hole become conduct electricity to forman outer cylinder-shaped conductor; (c) placing an electrical-resistantmaterial in the outer cylinder-shaped conductor to form anelectrical-resistant fill; (d) forming a second hole in theelectrical-resistant region, wherein the second hole has a diametersmaller than the diameter of the first hole; and (e) making the interiorof the second hole become conduct electricity to form an innercylinder-shaped conductor.
 48. The method of manufacturing a coaxial viahole as claimed in claim 47, wherein in said step (b), making theinterior of the first hole become conduct electricity to form an outercylinder-shaped conductor by plating.
 49. The method of manufacturing acoaxial via hole as claimed in claim 47 or 48, wherein in said step (e),making the interior of the second hole become conduct electricity toform an inner cylinder-shaped conductor by plating.
 50. The method ofmanufacturing a coaxial via hole as claimed in claim 47 or 48, whereinin said step (e), making the interior of the second hole become conductelectricity to form an inner cylinder-shaped conductor by placingconductive paste.